Tanzania is one of the most affected countries in sub-Saharan Africa by HIV/AIDS and TB. We propose to train future leaders to conduct research in epidemiological, operations and health services, and clinical research of HIV/AIDS and TB in Tanzania. Based on an in-depth needs assessment we identified training gaps in three principle areas: (1) research methods including quantitative, qualitative, and cost-effectiveness research methods; (2) substantive knowledge of prevention, care and treatment of HIV/AID S and TB; and (3) Research Systems Strengthening that include training on bioethics, grant writing, and manuscript development. This training initiative will be undertaken by Muhimbili University of Health and Allied Sciences and Harvard School of Public Health, in partnership with the National Institute of Medical Research, Ifakara Health Institute, the Ministry of Health, and the Tanzania Commission for AIDS. Over more than a decade, we have developed a multidisciplinary team of investigators that advanced research training related to discovery of knowledge including the safety and efficacy of various interventions. Over the next 5 years we propose to focus on building capacity in the area of clinical, operational, and health systems research that would advance the implementation of evidence-based best practices on HIV/AIDS and TB. Training will be provided in Boston and Dar es Salaam, with the latter assuming greater proportion of the training activities over the five years of the program. Trainees will benefit from exposure to a broad range of existing collaborative projects between the proposed partners including epidemiological and laboratory studies, randomized clinical trials, operations research programs, and existing datasets. These resources will provide unique opportunities for research training, including practical aspects of study design and implementation and refinement of skills in data analysis and manuscript development. We will regularly monitor our performance and strive to develop a system for sustainable training activities in Tanzania.